1. Field of the Invention
The present invention relates to a spinning processing method for processing cylindrical parts such as a motor rotor, a clutch drum, or the like, and a rotor shaft.
2. Background Information
Generally, cylindrical parts such as a motor rotor, a clutch drum, or the like are manufactured according to the forging-cutting method. Also, when manufacturing cylindrical parts by employing the spinning processing method, the splitting apart method of using one piece of a disc-shaped sheet as the working material, dividing the peripheral edge of this sheet into two in its thickness direction, and splitting apart this divided material has been adapted (e.g., refer to Japanese Patent No. 4123705).
Here, “spinning process” refers to a plastic process method, which carries out a molding by pressing a sheet-shaped material (a blank) in a rotating die (a mandrel) using a processing roller or a spatula.